The Collaborative International Dictionary of English v.0.48:

coralroot \coralroot\ n.
   a European bittercress (Dentaria bulbifera) having a
   knotted white rootstock.

   Syn: coral-root bittercress, coralwort, Cardamine bulbifera,
        Dentaria bulbifera.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

coralroot
    n 1: European bittercress having a knotted white rootstock [syn:
         coral-root bittercress, coralroot, coralwort,
         Cardamine bulbifera, Dentaria bulbifera]